/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.jackrabbit.webdav.observation;

import org.apache.jackrabbit.webdav.DavException;

/**
 * <code>SubscriptionManager</code> interface.
 */
public interface SubscriptionManager {

	/**
	 * Retrieve the
	 * {@link org.apache.jackrabbit.webdav.observation.SubscriptionDiscovery}
	 * object for the given resource. Note, that the discovery object will be
	 * empty if there are no subscriptions present.
	 * 
	 * @param resource
	 */
	public SubscriptionDiscovery getSubscriptionDiscovery(
			ObservationResource resource);

	/**
	 * Retrieve the list of events that occured since the last poll.
	 * 
	 * @param subscriptionId
	 *            indentifier for the subscription
	 * @param timeout
	 *            the time in milliseconds to wait at most for events if none is
	 *            present currently.
	 * @param resource
	 * @return
	 */
	public EventDiscovery poll(String subscriptionId, long timeout,
			ObservationResource resource) throws DavException;

	/**
	 * Create a new <code>Subscription</code> or update an existing
	 * <code>Subscription</code>..
	 * 
	 * @param info
	 * @param subscriptionId
	 * @param resource
	 * @return <code>Subscription</code> that has been created or updated
	 * @throws DavException
	 *             if the subscription fails
	 */
	public Subscription subscribe(SubscriptionInfo info, String subscriptionId,
			ObservationResource resource) throws DavException;

	/**
	 * Unsubscribe the <code>Subscription</code> with the given id.
	 * 
	 * @param subscriptionId
	 * @param resource
	 * @throws DavException
	 */
	public void unsubscribe(String subscriptionId, ObservationResource resource)
			throws DavException;
}